Fiber-optic conversion module

Abstract

A fiber-optic conversion module is provided as part of a lighting device on a vehicle. The module includes optical fibers with connectors, a light exit head, and a converter mounted on a cooling element. Shorter wavelength excitation light is fed to the optical fibers that emit the excitation light towards the converter arranged at an angle relative to the beam direction, at a light spot that remits useful light in a radiation angle in form of a cone of useful light and reflects excitation light as a Fresnel reflection substantially outside the cone of useful light, where Fresnel reflection is made harmless by a light stop.

What is claimed is: 
     
       1. A conversion module for converting shorter wavelength excitation light into longer wavelength converted light, comprising:
 a converter arranged at an angle relative to a beam direction of the shorter wavelength excitation light and used for converting the shorter wavelength excitation light into the longer wavelength converted light, for emitting useful light at a useful radiation angle, the shorter wavelength excitation light having a part that is reflected into a region outside the useful radiation angle; 
 a cooling element for accommodating the converter, the converter being mounted on a surface of the cooling element in a heat conductive and mechanically stable connection; and 
 an exit window for useful light provided with a light stop for the part of the shorter wavelength excitation light that is reflected into the region outside of the useful radiation angle of the useful light. 
 
     
     
       2. The module as claimed in  claim 1 , wherein the shorter wavelength excitation light mostly enters into the converter where it is converted into the longer wavelength converted light, the longer wavelength converted light being emitted together with scattered excitation light into the useful radiation angle as the useful light. 
     
     
       3. The module as claimed in  claim 1 , wherein the exit window is defined by a cover sheet, the cover sheet comprising the light stop, which together with the converter forms a light trap for collecting the part of the shorter wavelength excitation light that is reflected at the converter. 
     
     
       4. The module as claimed in  claim 1 , further comprising a cover sheet, through which the useful light passes in an operational mode. 
     
     
       5. The module as claimed in  claim 1 , further comprising measures for optically monitoring the converter. 
     
     
       6. The module as claimed in  claim 5 , further comprising measures for optically monitoring the cover sheet. 
     
     
       7. The module as claimed in  claim 1 , wherein the cooling element is connected to a heat sink via a heat conduction path. 
     
     
       8. The module as claimed in  claim 1 , further comprising a focusing optical element configured to feed, in an operational mode, the short wavelength excitation light to the converter. 
     
     
       9. The module as claimed in  claim 8 , wherein the focusing optical element is configured to focus divergent short wavelength excitation light onto the converter. 
     
     
       10. The module as claimed in  claim 1 , further comprising at least one optical fiber having a light exit end configured to emit the shorter wavelength excitation light in the beam direction. 
     
     
       11. The module as claimed in  claim 1 , further comprising at least one excitation light source to emit the shorter wavelength excitation light in the beam direction. 
     
     
       12. A conversion module for converting shorter wavelength excitation light into longer wavelength converted light, comprising:
 a converter arranged at an angle relative to a beam direction of the shorter wavelength excitation light, the converter being configured to convert the shorter wavelength excitation light into the longer wavelength converted light, and the converter being configured to emit the shorter wavelength excitation light at a useful radiation angle; 
 a cooling element in thermal communication with the converter; and 
 an exit window having a light stop defining a radiation trap for Fresnel reflection of a part of the shorter wavelength excitation light from the converter, the radiation trap being between a lower surface of the light stop and at least one of the cooling element and the converter. 
 
     
     
       13. The module as claimed in  claim 12 , wherein the shorter wavelength excitation light mostly enters into the converter where it is converted into the longer wavelength converted light, the longer wavelength converted light is emitted together with scattered excitation light into the useful radiation angle as useful light. 
     
     
       14. The module as claimed in  claim 12 , further comprising at least one optical fiber having a light exit end configured to emit the shorter wavelength excitation light in the beam direction. 
     
     
       15. The module as claimed in  claim 14 , further comprising a light exit head for supporting the light exit end and the converter. 
     
     
       16. The module as claimed in  claim 14 , further comprising at least one excitation light source, the optical fiber having a light entrance end at least one, the at least one excitation light source being configured to emit the shorter wavelength excitation light into the light entrance end. 
     
     
       17. The module as claimed in  claim 12 , further comprising a cover sheet, through which the useful light passes. 
     
     
       18. The module as claimed in  claim 12 , further comprising at least one excitation light source configured to feed the shorter wavelength excitation light to the converter via a focusing optical element. 
     
     
       19. The module as claimed in  claim 18 , wherein the focusing optical element is configured to focus divergent light originating from the at least one excitation light source. 
     
     
       20. The module as claimed in  claim 12 , wherein the converter is mounted on a cooled surface of the cooling element. 
     
     
       21. The module as claimed in  claim 15 , wherein the light exit head comprises a lower part, an upper part, and an insert. 
     
     
       22. The module as claimed in  claim 21 , wherein the insert has a front face that forms a step across which an exiting beam of the shorter wavelength excitation light passes through a free space between the front face and an inclined upper surface of the converter. 
     
     
       23. The module as claimed in  claim 12 , further comprising a frangible conductive path on the exit window, wherein, when the exit window undergoes damage, the frangible conductive path is interrupted. 
     
     
       24. The module as claimed in  claim 12 , wherein the module is configured for use as a lighting device or an automobile headlight.